Forced-draft furnace



jan. i3, 1925.-

'1523,3? w. H. PALMER FORCED `DRAKT FURNACE original Filed om.. 22. 1921 2 sheets-sheet 1 Jan. 13, 1925.

W. H. PALMER FORED QRAFT FURNAGE 2 Sheets-Sheff(l 2 original Filgdgoct. 22. 1921 Patented dan. 13, 1925.

staats WILLIAM I-I. PALMER, OF PITTSBURGH, PENNSYLVAIA.

FORCED-DRAFT FURNACE.

Application filed october 22, 1921, Serial No. 509,582. Renewed August 15, 1924.V

To all whom t may concern:

Be it known that I, VrLLIAM PALMER, a citizen of the United States, and residing in the city of Pittsburgh, in the county of Allle,- gheny and State of Pennsylvania, have in.- vented or discovered a new, useful, and ImprovedForced-Draft Furnace, of which the following is a specification. l

My invention consists in certain new and useful improvements in forced draft furnaces, such, for instance as boiler furnaces.

The object which I havel in view is the provsion of improved means for supplying an artificial draft to the fuel bed, and for properly distributing the same. More particularly my invention is designed for use in connection with structure which Vsupports the fuel bed but does not permit the fuel or `the products lof combustion to pass downA through lthe grate structure, the necessary air fbeing supplied by artificial draft through openings in the grate surface.

For the purpose of properly distributing theartificial draft I provide a novel and improved air-chamber structure located 4bev neath the grate and which is particularly adapted for the purpose above referredto, although the same may be advantageously used in connectionwith the ordinary spaced apart grate bars.

I also show a new and improved form of closed grate bar structure and assemblage ofthe same to constitute the closed fuel supporting platform or grate.

I also show a new and improved furnace construction in which various features of my invention are employed.

Other novel features of construction and arrangement of parts will appear from the following descriptions.

In the accompanying drawings, which are however merely intended to illustrate the principles of my present invention without limiting the scope of the latter to t-he con struction shown, Fig. l is a sectional perspective showing a furnace fitted with the preferred' form Aof my invention; Fig. 2 is a partial plan view of the same, some of the grate bars being removed to more clearly show parts; Fig. 3 is an enlarged perspective of one of the air-chambers, and Fig. l is an enlarged sectional view showing two grate bars superimposed over an air-chamber which is located in the furnace pit.

a closed grate rIhe following is a detailed description of the drawings; y i

A represents the front wall of the furnace provided with a plurality of spaced apart pit doors l, while 2 are the fuel doors, one of the same being' preferably positioned above each of the pit doors.

B represents the bridge `wall and C one 4 ends of the grate bars D, which bars, be-

tween the said supporting flanges, are provided with depending, vertical'side walls t. The tops 5 of said bars yare horizontal except at the front where they are upwardly inclined toward the front wall A as shown in Fig. 1. l

The l grate bars herein shown are similar to the grate bars shown and described in Letters Patent of the United States No, 958,971', issued to me on May 24, v1910,42(- cept that in the present case the bottomsV of the bars `are shown open, the bars being substantially inverted channels.

The top walls 5 of the bars are provided with apertures 6 in which are seated Vthe cover plates 7, arcuate air spaces 8 being provided between the` walls of the apertures and said plates, as is more fully described in said Letters Patent.

The bars D are assembled in close proX- imity, the spaces between adjacent bars being filled with asbestus cement 9, or some other refractory material. y

To properly support the packing or filling 9, between the bars D, I prefer to provide a metal bar 10, which is preferably an inverted channel or V bar having its ends suitably supported from the front wall and` bridge wall by means of flanges or brackets, not shown but similar to the flanges 3 which support the ends of the grate bars D.

It is thus seen that the fuel is supported on a substantially tight platform downy through which the fuel or products of combustion can not pass, but up through which the air necessary for combustion is introduced by means of the openings 8.

E represents an air manifold which is connected to a fan or some other convenient source of artificial draft. Said manifold is shown in its prefered form-a duct or passageway underneath the floor of the pit F and running transversely of the same near the bridge wall B.

At intervals vertical ducts 11 lead up from the said manifold into the interior of said pit, said ducts being alined between adjacent pit doors 1.

H represents the air-chamber members positioned in the pit F so as to receive the air from the ducts 11.

The preferred form of said air-chamber is that of a metal box of triangular shape having its ends closed and having an open bottom which is placed over Vone of the ducts 11. Thus, as shown in Fig. 3, the boxes H have sides 12 formed by inclined plates whosel upper ends are bent into a vertical plane and bolted together forming a 'ridge flange 13. The ends of the box are formed of the triangular plates 1a. One of said open bottom boxes is placed over each of the ducts 11, with the rear end of the box fiat against the bridge wall and its ridge extending up into, and preferablyv aiding in the supportof the angle bar 10.

I is a brick partition wall built up from the floor of the pit to the angle bar 10, and extending from the central front of the box H to the front wall of the pit. The wall I may also assist in supporting the Y bar 10. It is thus seen that the air-chamber H and the partition walls I divide the pit into a plurality of compartments, access to which is obtained through the respective pit doors 1.

The side walls of each air-chamber H are provided with longitudinally elongated air ports 15 which are closable by means of the shutters 16 slidably mounted in the guide plates 17 attached to the box. 18 represents operating' rods having their inner ends attached to said shutters and their outer ends protruding through holes in the front wall of the furnace and looped to form the handles 19. The shutters are opened by being moved toward the bridge wall, and when fully open the handles 19 impinge against the front wall of the furnace. To close or partially close said ports, the handles are pulled outwardly, so that a protruding handle will remind the fireman that the corresponding air port is closed, or partially closed, as indicated by the degree of protrusion of the handle relative to the front wall of the furnace.

It is evident that when the ports in the adjacent walls of a pair of adjacent airchambers are open, the artificial draft will be supplied to the pit compartment dened between said chambers and the corresponding partition walls, and that the amount of said draft may be regulated by the adjustment of the port shutters; or the draft may be cut off from said compartment by moving said shutters into position to entirely close said ports.

Thus the draft may be admitted to the portion of the grate platform over any the air openings in the gra-te bars, as the same will slide down the exterior walls ofthe chamber to the floor of the pit whence it may be removed through the pit doors.

I prefer to position the air escape ports at the opposite ends of the air chambers from the inlet ducts, thus preventing any dust which .may enter the air chambers from reaching the ducts or manifold.

The apparatus is extremely simple and' can readily be repaired when necessary.

Althougln for the sake of clearness of l-.

soi

lustration of the principles of my invein tion, I have minutely described'the en ibodi-4 ment of the same shown in the drawings, I f

do not wish to limit myself thereby, but claim broadly Y 1. In a furnace, theV combination of a fuel platform composed of closed grate bars, partition walls running from the front wall to the bridge wall, and fromV the bottom of the pit to the fuel platform, dividing the pit into a plurality of separate compart-` ments, air chambers interposed in said partition walls and provided with ports communicating with the ash pit compartments on either side, valves for said ports, means for the individual operation of said valves from without the furnace, and means for supplying forced draft to said air chamf bers.

2. In a furnace, the combination of a forced draft fuel platform closedagainst the downward passage of fuel therethrough and comprised of a plurality of grate bars of inverted channel shape, said grate bars being provided With openings for the upward escape of air therethrough,` vertical partitions running from the front wall to the bridge wall dividing the pit into a plurality of compartments Vwhich are roofed bythe fuel platform, air chambers in said p-artitions, ports in the sidewalls of said air chambers communicating with the compartments on either side of the same, valves for said ports, means for the individual operation of said valves from without the furnace, and means for supplying forced draft to said air chambers. Y Y

3. In a furnace, the combination of afuel platform composed of Vclosed grate bars having openings for the upwardV passage of air, partitions runningfrom the frontA 130 wall to the bridge wall dividing the pit beneath the platform into a plurality of oomoperation of said valves from Without said partrnents7 air boxes interposed in and furnace, and means for supplying air blast forming parts of said partitions, said air to said boxes. 10 boxes having upwardly converging side Signed at Pittsburgh, Pa., this 20th day 5 Walls provided with ports eolninunlcating of October, 1921.

with the compartments at their sides, valves for said ports, means for the individual WILLIAM H. PALMER. 

